158 



ELEMENTS OF STRUCTURAL BOTANY. 



2G0. Whilst looking at the parts of plants just sub- 

 mitted to examination, it must have struck you that the 



interior of the cell 

 presents a very dif- 

 ferent appearance in 

 different cases. The 

 Potato section, for 

 example, is not at all 

 like the Moss-leaf 

 section in the matter, 

 of oell-eontetds, and 

 the cells of the Elder- 

 pith appear to be 

 quite empty. We 

 shall discuss these 

 differences presently. 

 In the meantime let 

 us study the appear- 

 ance of some cells 



taken fresh from soma part of a plant where growth is 



actually going on— say the point of a new rootlet. If our 



sectiom is taken 



near enough to 



the point we shall 



get cells" which 



have just been -^ ^if^ \ 



formed. Such a ^'^^^®- Fig. 217. 



section is very" well shown in Fig. 218. Here the cells 



are seen to be completely filled with liquid liaving a 



Fig. 215.— Cells from leaf of a Moss containing protoplasm and chlorophyll- 

 granules. 

 Fig. 216. — Hair from Petunia leaf. Fig. 217. — ^Hairs from Geranium leaf. 



